The present invention is directed toward a immunochromatographical test device and more particularly, toward a device for detecting the presence of particular substances in a fluid sample.
Various methods for detecting the presence of a particular substance or substances in a fluid sample through the use of immunochemistry are known. Typically, these methods detect both antibodies and antigens and are generally referred to as immunoassays.
For example, U.S. Pat. No. 4,632,901 to Vilkirs discloses an immunoassay device comprising an antibody bound to a porous membrane and to which is added a liquid sample. As the liquid flows through the membrane, target analyte binds to the antibody. Visual detection of labeled antibody indicates the presence of target antigen analyte in the sample. This device, however, requires several steps and a certain amount of expertise by the user in order to avoid inaccurate results.
U.S. Pat. No. 5,656,448 to Kang et al. discloses a dipstick immunoassay device which incorporates the use of symbols in the test zone and enzyme labeled antibodies to detect analytes in a sample of biological fluid. This immunoassay device, however, is complicated to use.
The present invention is designed to overcome the deficiencies of the prior art discussed above. It is an object of the present invention to provide a test device which determines the presence or absence of certain substances in a test sample.
It is a further object of the present invention to provide a test device which is easy to use and provides accurate results.
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided a cap, an absorbent pad, a membrane, a test strip, a holder, and a housing. The housing contains the membrane and the test strip which contains immunoreagents. Secured to the holder is the absorbent pad which contains the sample to be tested. The cap fits over the holder and the holder fits within the housing. When the absorbent pad contacts the membrane, the membrane indicates that a proper amount of the sample has been collected. When the absorbent pad contacts the test strip, a reaction, if any, can be observed via a window formed within the housing.
Other objects, features, and advantages of the invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the drawings.